Transmission woes

[crazymike]

I purchased a basket case 87ish CR250 off of a shop teacher several years ago. I got most of it ready and got all my parts together but I could never get the transmission pressed together.

Fast forward 5-6 years. I tried several times to press the transmission back together but I just couldn't get the cases to go together. Finaly today my brother tried to press it and it still wouldn't go (yes I know you arn't supposed to force cases) I took everything back apart and spent a good 4-5 hours in the cold trying to figure out why.

Turns out the crank bearings I bought were for multiple years. And to use them on this bike you had to remove two circlips :p

After kicking myself several times for not noticing this earlier I got the bottom end bolted together and the shifter shaft assembled.

The trasnmission spins fine, and when I push the lever up and down it sounds like it's shifting something. But I can't tell if it's actually shifting and I can't seem to find a neutral. Is this normal? Do I need to get the clutch, etc... back on before I can find neutral?

I put everything back together according to the manual but I really don't want to get the bike running only to have to take it to pieces again.

Any tips, advice would be great, thanks.

(I need to get this bike sold in a hurry because I'm desperate for the money :p)

 

[YZ165]

If you spin the shaft that the clutch basket bolts to, and hold the output shaft, you should be able to find neutral. If you are not holding the output shaft, it will spin and "look" like the trany is still in gear. Try that, if you put the tranz back together right, you should be able to find neutral and all the gears. It might want to have a buddy help, it may require more than two hands. Good luck, YZ165

P.S. This should probably be in "general bike repair", don't be surprised if it gets moved.

 

[crazymike]

If you spin the shaft that the clutch basket bolts to, and hold the output shaft, you should be able to find neutral. If you are not holding the output shaft, it will spin and "look" like the trany is still in gear. Try that, if you put the tranz back together right, you should be able to find neutral and all the gears. It might want to have a buddy help, it may require more than two hands. Good luck, YZ165

P.S. This should probably be in "general bike repair", don't be surprised if it gets moved.

thanks, I will try that/

And yes, I realized I was in the wrong forum about 3 seconds after I hit submit :p

 

[reelrazor]

It seems to me that most CR's are kinda hard to find the top couple gears when you bench test the trans. Basically if you can find 1,n,2,3, you are good to go. YZ165 is right in what he said, hang onto the shaft and try it.

Neutral can be tricky, and just like when they are running, it is easier to get from 1-n, than 2-n.

 

[crazymike]

I took it apart again, double checked everything and then put it back together. I was able to find neutral eventually.

Now I have a new problem. At some point someone has ever so slightly mushroomed the crank shaft and now I can't get the gear back on. I tried heating the gear with a propane torch and sliding it over with no luck. I don't want to replace the crank shaft, is there any thing I can do?

It's not mushroomed horrible, just enough to stop the gear from going back on.

Should I try heating the gear with acetelyne?

 

[reelrazor]

It's not mushroomed horrible, just enough to stop the gear from going back on.

Should I try heating the gear with acetelyne?

NO. Many of those gears(esp. Honda) will only take soooo much heat then they will crack. It is not likely that you will expand the gear enough anyway.

You are going to need a sharp file and patience. File it evenly all around, try the gear, and repeat until the gear goes on. Try to keep your filing as minimal as possible. You will start to see a burnished spot wherever the gear is tight on the shaft. Keep working those tight spots away and at some point the gear will slide on. If you can't do this without leaving at least 2/3 of the original surface under the gear you are screwed.

Ohh, damn, is the mushroom the threads? You will have to get a metric thread file and work it down with that.

The crank is haaaard, it pays to have a GOOD mill file, and only bear down a little bit. Don't backstroke the file, they only cut in one direction(away on the vast majority of them). If you draw the file backwards it will dull rapidly. Files are like knives, you can only do good work with them if they are sharp.

 

[crazymike]

NO. Many of those gears(esp. Honda) will only take soooo much heat then they will crack. It is not likely that you will expand the gear enough anyway.

You are going to need a sharp file and patience. File it evenly all around, try the gear, and repeat until the gear goes on. Try to keep your filing as minimal as possible. You will start to see a burnished spot wherever the gear is tight on the shaft. Keep working those tight spots away and at some point the gear will slide on. If you can't do this without leaving at least 2/3 of the original surface under the gear you are screwed.

Ohh, damn, is the mushroom the threads? You will have to get a metric thread file and work it down with that.

The crank is haaaard, it pays to have a GOOD mill file, and only bear down a little bit. Don't backstroke the file, they only cut in one direction(away on the vast majority of them). If you draw the file backwards it will dull rapidly. Files are like knives, you can only do good work with them if they are sharp.

k, thanks.

I have to dig out the file. I tried a bit with sandpiper and it was sanding down, but I don't have 4 years. I will try with a file and see what happens.

 

[crazymike]

Well, I finaly got the gear on. Then I noticed a rather large empty spot in the casing. HMM, what goes in there... ahh yes, Kick start assembly. Except I can't find it anywhere :p

Sometimes I wonder why I buy basket cases :p